1. Field of the Invention
This invention relates to an electrical connector of the sort used with temporary cardiac pacing wires.
2. Description of the Prior Art
A typical temporary cardiac pacing wire normally has the following elements: a sharp Keith-type straight cutting needle; a relatively soft multi-strand surgical steel wire having a soft plastic coating therearound; and a circular taper point needle. Both needles are swaged or otherwise connected directly onto the conducting steel wire. Wires of this sort are manufactured by the A & E Medical Division of the Alto Development Corporation of Farmingdale, N.J. The Model M-26 is one example. Another example is described in U.S. Pat. No. 4,010,756. The Keith-type straight needle described in that patent includes a weakened zone therein so that it may be snapped apart. The remaining shank portion is then used as a male lead for an electrical connector. The same result can be achieved by cutting the shank of a conventional Keith-type needle with a pair of diagonal pliers. The lead thus formed is attached to a therapeutic or diagnostic medical instrument by use of alligator clip leads or by plugging the lead directly into the hole and locking thumbscrew connections common to a great many pacemaker designs. These widespread methods of connecting the temporary pacing wires to the instrumentation leaves a lot to be desired because the connections are not electrically insulated or protected from contaminants; and they do not provide for protection of the lead when it is not in use. Connectors like the ones described above are in use today on a very limited basis. Most are custom-built and none use the lead formed from the shank of a Keith-type needle. Instead the Keith-type needle is completely cut off and the center conducting wire is exposed by stripping the insulation. The most common connector is believed to be manufactured by the AMP Corporation. That connector is described on pages 16 and 17 of a book entitled "Diagnosis and Treatment of Cardiac Arrhythmias Following Open Heart Surgery" published in 1980 by The Futura Publishing Company, Inc. of Mount Kiscoe, N.Y. The authors are Albert L. Waldo, M.D. and William A.H. MacLean, M.D. According to that disclosure the Keith-type straight needle is cut off completely after the wire electrode has been passed through the anterior chest wall of the patient. A small black rubber sealing grommet is placed on the wire then after stripping the wire a gold pin is attached to the wire using a special crimping tool. The pin is then inserted into a long, lightweight nylon female connector. The connector thus formed is relatively static resistent and splash-proof. However, the process for forming the connector is somewhat complicated and requires a special crimping tool. It is believed that the present invention overcomes some of the problems inherent in such a prior art system.